33.4 MPG, Down over 10MPG

i basically have the same problem as everyone else and drive 180 miles/day and drive like the rest of you. i'm also trying to find solutions to this problem. Has anyone found the solution yet? dareniott?

 

What might this problem be? Care to give us any details?

Tom

 

it started back in nov/dec 09. i drive 80mph 180miles/day and get 45-46 mpg. My driving style hasn't changed but my mileage has gone down to 37-38mpg. I fill up at the same Shell gas station every time roughly 8.5 gal. I take the same route but live in the hills, but again I haven't changed anything for the past year and for the past 2 months these changes have come. I got new tires right before xmas, michelin x from costco and psi at 40. i do oil changes every 5k with tire rotations.

 

Have you thought about winter blend fuel and your new tires which could take 1,000 milers or more to break in?

 

I noticed the exact drop in MPG starting from December 2009. I live in Iowa and it has been a pretty bad winter I would say. But I also notice MPG beginning to climb up as soon as temps go above freezing. So, I am not too worried at the moment. I do block the grille. However, tire pressure could have dropped -- haven't checked in 2 months! Tire pressure was 38/36.

Update[Feb 2010]: Increased the tire pressure to 42/40 from 38/36 but not much difference in MPG.
Update[Mar 2010]: Weather improved. Getting 45 MPG already at 40-55 deg F. Also, stopped using Ethanol mix. But I think, weather is the main reason.

 

ok since i'm new i couldn't fine the grille blocking thread or what/how to do. can someone link it please. thanks. when this is done how much of a bump do people usually see? thanks.